Poor man's knex/bookshelf pagination

paginate.js

var Promise, defaultPageSize, paginate;

Promise = require('bluebird');

defaultPageSize = 20;

paginate = function(knex) {
  return function(query, paginationOptions, options) {
    var limit, model, offset, page, pageSize, totalPromise, totalQuery;
    if (query.fetchAll != null) {
      model = query;
      query = model.query();
    }
    totalQuery = knex.count().from(query.clone().as('inner'));
    totalPromise = totalQuery.then(function(rows) {
      return rows[0].count;
    });
    page = paginationOptions.page, pageSize = paginationOptions.pageSize, offset = paginationOptions.offset, limit = paginationOptions.limit;
    if (pageSize == null) {
      pageSize = defaultPageSize;
    }
    if (offset == null) {
      offset = 0;
    }
    if ((page == null) || page < 1) {
      page = 1;
    }
    page += Math.floor(offset / pageSize);
    limit = limit != null ? limit : pageSize;
    offset += (page - 1) * pageSize;
    query.offset(offset);
    if (limit > 0) {
      query.limit(limit);
    }
    return Promise.all([(model != null ? model.fetchAll(options) : void 0) || query, totalPromise]).spread(function(data, total) {
      return {
        pagination: {
          total: total,
          pageSize: pageSize,
          offset: offset,
          limit: limit,
          page: page,
          pageCount: Math.ceil(total / pageSize)
        },
        data: data
      };
    });
  };
};

module.exports = paginate;